Metallic elements adapted to come in contact with melted glass



April 25, 1967 METALLIC ELEMENTS ADAPTED TO COME IN CONTACT WITH MELTED GLASS B. LAURENT ETAL Filed OCt. 25, 1963 TIME /A/ Had/e5 I g I W I INVENTORS 4/ i flaw/42p [Aw e541? 7a 140 2/0 250 39 2 350 [Gag FEZEN/(a 7,445 //1/ Hal/es BY ATTORNEY United States Patent 3,316,074 METALLIC ELEMENTS ADAPTED TO COME IN CONTACT WITH MELTED GLASS Bernard Laurent, Paris, and Igor Fezenko, Mitry-Mory,

France, assignors to Compagnie de Saint-Cobain, Neuilly-sur-Seine, France, a corporation of France Filed (let. 25, 1963, Ser. No. 319,050 Claims priority, application France, Nov. 6, 1962, 914,567 Claims. (Cl. 65-1) It is the object of the present invention to provide refractory alloys which present particularly interesting physical and mechanical properties.

The alloys according to the invention contain the following principal constituents: chromium, nickel, niobium (part of which may be rep-laced by tantalum), tungsten, carbon and iron, the proportions of these different constituents being within the following limits:

Chromium: 25% to 33%, and preferably 28% to 32% Nickel: 45% to 53%, and preferably 48% to 53% Niobium: 3.5% to 6%, and preferably 3.5% to 5% Tantalum: present in the niobium in an amount up to 0.5% Tungsten: 1% to 5%, and preferably 3% to 5% Carbon: 0.3% to .6%, and preferably 0.4% to 0.5% Iron: the remainder These alloys may also include manganese in an amount up to 2%, and preferably 0.5% to 1.5%, silicon up to 0.5%, and boron from 0.1% to 0.4%.

By way of example, the following formulation specifies a particular composition of an alloy according to the invention:

Percent The alloys according to the invention have a low coefficient of expansion which varies relatively little with the temperature. Thus it is that an alloy according to the above example has an expansion coeificient which varies from 13.00 at ordinary temperature to 17.25 10 at 1100 C.

The alloys also have particularly interesting properties from the point of view of flow and corrosion resistance.

So, the alloy of the above example, subjected to flow tests corresponding to a load of 2 kg./mm. at a temperature of 1050" C. does not give rise to breakage until after a very long time, about 640 hours; while the alloys customarily used have periods before breakdowns of about 200 hours under the same conditions.

In the accompanying drawings,

FIGS. 1 and 3 are graphs indicating comparative results of flow and corrosion resistance, respectively, attainable by the use of alloys in accordance with the present invention, and conventional alloys as known in the prior art; and

FIG. 2 is a vertical sectional View of a rotary centrifuge assembly for handling molten glass which is adapted to be fabricated from alloys in accordance with the invention, which are characterized by a high degree of resistance to the corrosive effects of molten glass.

The curves of FIG. 1 of the attached drawings show the evolution of flow at 1050 C. under 2 kg./mm. of a 3,316,074 Patented Apr. 25, 1967 well known alloy, represented by curve A which consists of:

Percent Chromium 26.6 Nickel 52.0 Carbon 0.43 Tungsten 5.6 Silicon 1.0 Manganese 1.06 Iron (the remainder) 13.31

In comparison thereto, curve B portrays the behavior of an alloy according to the invention having the composition of the above specific example. The abscissas, indicating the time in hours, are in logarithmic scale, and

r the ordinates corresponding to the el-ongations in percent,

are in decimal scale.

The invention also provides for the application of the above alloys to the production of metallic pieces or organs designed to be in contact with melted glass, for example, receivers or vessels, condensers, electrodes, etc. It is particularly concerned with the obtention in metallic organs which have orifices, in general of small diameter, through which the melted glass flows at high temperature, these pieces or organs themselves being brought to a high temperature.

The invention has for its aim the use of these alloys especially for the attainment of hollow rotating bodies which are employed in the production of glass fibers, and which have a peripheral band or wall provided with a plurality of orifices through which the melted glass is projected in the form of filaments which are then drawn out into fibers. Such hollow bodies operate under particularly diflicult and demanding conditions, in view of the very high temperatures to which they are raised, and especially by reason of the high temperature of the gases in contact with the outside of the peripheral band.

In FIG. 2 of the attached drawings, there is shown in axial cross section such a rotating body 1 whose peripheral band 2 is pierced by a great number of orifices 3. The melted glass 4 is supplied to a distributing organ 5, in the shape of a basket, the vertical wall of which is also provided with orifices 6. Basket 5 is carried along in rotation by the rotating body 1 and the melted glass is projected through orifices 6 onto the internal face of peripheral wall 2, the glass being thus distributed substantially uniformly on that wall. Under the effect of centrifugal force, the melted glass is projected through orifices 3 in the form of filaments which are then drawn out into fine fibers. There is also shown a combustion chamber 7, of general annular shape, allowing combustion gases at high speed and high temperature to be directed, through an expansion orifice 8 arranged coaxially with the rotating body, into contact with the threads of material projected through orifices 3 and. to cause them to be drawn out into fine fibers.

As can be seen, such a rotating body, particularly its peripheral band, is subjected to very high temperatures requiring a great resistance to flow of the materials utilized, and, moreover, the glass, also at high temperature, exerts a great corrosive action when it passes through the orifices, as much on the rotating body as on the distributor basket.

The alloys according to the invention permit the useful life of these devices to be decreased to a substantial degree, that is, both the hollow centrifuge bodies as well as the distributor members therein, by reason of their high resistance to corrosion.

The curves of FIG. 3 portray the losses in weight in percent of centrifuge bodies of identical shape and dimensions formed of different alloys, corresponding to different periods of operation in hours.

It Curve C illustrates the functional behavior of a centrifuge body formed of a conventional alloy of the following composition:

Curve D illustrates the functional behavior of a centrifuge body formed of another well known alloy, and particularly one of the formulation set forth above for the conduct of the flow test represented by the specimen producing the curve A in FIG. 1.

Curve E illustrates the functional behavior of a centrifuge body when the same is formed of the specific alloy in accordance with the invention as set forth above in the first specific formula, and which produced the curve B in FIG. 1.

The tests above were conducted with molten glass of mean viscosity of 1100 poises, at a temperature of 1030 0., this glass having the following composition:

Percent S10 61.25 S 0.31 F6203 A1 0 4.00 CaO 8.50 Mgo 4.10 N3 0 12.55 K 0 0.49 B 0 5.20 BaO 1.60 F 2.50

It should be noted that, although the alloys according to the invention have a certain hardness, this hardness is not, however, such that they cannot be machined under normal conditions of standard refractory steels. It is also to be noted that, with alloys according to the invention, it is possible to manufacture distributor elements or baskets which are not welded and are manufactured by centrifugation while in a molten state.

We claim:

1. Metallic pieces formed with orifices of small diameter through which pass filaments of molten plastic material at high temperature having a strong corrosive influence on the metal, said pieces being formed, at least in part, of an alloy having good mechanical resistance and high corrosion resistance and consisting essentially of the following ingredients in the respective proportions by weight: chromium ranging from above 25% to 33%; nickel ranging from approximately 45% to 53%; a combined niobium and tantalum content ranging from approximately 3.5 to 6% with the tantalum content in minor amount ranging up to 0.5 tungsten from approximately 1% to 5%; carbon ranging from approximately 0.3% to less than 0.5%; with the remainder iron.

2. Metallic pieces formed with orifices of small diameter through which pass filaments of molten glass at high temperature having a strong corrosive influence on the metal, said pieces being formed, at least in part, of an alloy having good mechanical resistance and high corrosion resistance and consisting essentially of the following ingredients in the respective proportions by weight: chromium ranging from above 25% to 33%; nickel ranging from approximately 45% to 53%; a combined niobium and tantalum content ranging from approximately 3.5% to 6% with the tantalum content in minor 4 amount ranging up to 0.5%; tungsten from approximately 1% to 5%; carbon ranging from approximately 0.3% to less than 0.5%; up to 2% of manganese; up to 0.5% of silicon; boron ranging from 0.1% to 0.4%; and the remainder consisting essentially of iron.

3. Metallic pieces formed with orifices of small diameter through which pass filaments of molten glass at high temperature having a strong corrosive influence on the metal, said pieces being formed, at least in part, of an alloy having good mechanical resistance and high corrosion resistance and consisting essentially of the following ingredients in the respective proportions by weight: chromium ranging from approximately 28% to 32%; nickel ranging from approximately 48% to 53%; a combined niobium and tantalum content ranging from approximately 3.5% to 5% with the tantalum content in minor amount ranging up to 0.5%; tungsten from approximately 3% to 5%; carbon ranging from approxi mately 0.4% to less than 0.5%; manganese ranging from 0.5% to 1.5%; boron ranging from 0.1% to 0.4%; silicon up to 0.5%; and the remainder consisting essentially of iron.

4. A hollow rotatable metallic body having a peripheral wall with a plurality of orifices of small diameter through which are projected by centrifugal force thin filaments of molten glass, said body being composed of a metallic alloy having good mechanical resistance and high corrosion resistance and consisting essentially of the following ingredients in the respective proportions by weight: chromium ranging from above 25% to 33%; nickel ranging from approximately 45% to 53%; a combined niobium and tantalum content ranging from approximately 3.5% to 6% with the tantalum content in minor amount ranging up to 0.5%; tungsten from approximately 1% to 5 carbon ranging from approximately 0.3% to less than 0.5 with the remainder iron.

5. A hollow rotatable metallic body having a peripheral wall with a plurality of orifices of small diameter through which are projected by centrifugal force thin filaments of molten glass, said body being composed of a metallic alloy having good mechanical resistance and high corrosion resistance and consisting essentially of the following ingredients in the respective proportions by weight; chromium ranging from above 25% to 33%; nickel ranging from approximately 45 to 53%; a combined niobium and tantalum content ranging from approximately 3.5 to 6% with the tantalum content in minor amount ranging up to 0.5%; tungsten from approximately 1% to 5%; carbon ranging from approximately 0.3% to less than 0.5%; up to 2% of manganese; up to 0.5% of silicon; :boron ranging from 0.1% to 0.4%; and the remainder consisting essentially of iron.

References Cited by the Examiner UNITED STATES PATENTS 2,540,107 2/1951 English et al. 17l 2,587,275 2/1952 Bash 75171 2,607,170 8/1952 De Vries 75l71 3,031,717 5/1962 Levecque et al. 65--15 FOREIGN PATENTS 547,402 10/1957 Canada. 2,408,771 10/1946 Germany.

HYLAND BIZOT, Primary Examiner.

WINSTON A. DOUGLAS, DAVID L. RECK,

Examiners.

C. M. SCHUTZMAN, R. O. DEAN,

Assistant Examiners. 

1. METALLIC PIECES FORMED WITH ORIFICES OF SMALL DIAMETER THROUGH WHICH PASS FILAMENTS OF MOLTEN PLASTIC MATERIAL AT HIGH TEMPERATURE HAVING A STRON CORROSIVE INFLUENCE OF THE METAL, AND PIECES BEING FORMED, AT LEAST IN PART, OF AN ALLOY HAVING GOOD MECHANICAL RESISTANCE AND HIGH CORROSION RESISTANCE AND CONSISTING ESSENTAILLY OF THE FOLLOWING INGREDIENTS IN THE RESPECTIVE PROPORTIONS BY WEIGHT: CHROMIUM RANGING FROM ABOVE 25% TO 33%; NICKEL RANGING FROM APPROXIMATELY 45* TO 53%; A COMBINED NIOBIUM AND TANALUM CONTENT RANGING FROM APPROXIMATELY 3.5% TO 6% WITH THE TANTALUM CONTENT IN MINOR AMOUNT RANGING UP TO 0.5%; TUNGSTEN FROM APPROXIMATELY 1% TO 5%; CARBON RANGING FROM APPROXIMATELY 0.3% TO LESS THAN 0.5%; WITH THE REMAINDER IRON. 